1. Field of the Invention
The present invention relates to coronary angioplasty devices and procedures, and particularly to a system and method for removing blood containing contrast media, or dye, that provides for the removal of the contrast media used during angioplasty procedures from the coronary sinus of a patient's heart before the blood containing the media enters the right atrium and circulates through the bloodstream to the kidneys, potentially causing contrast-induced nephropathy (CIN).
2. Description of the Related Art
Percutaneous transluminal coronary angioplasty is frequently used in treating coronary atherosclerosis, which produces areas of blockage within a coronary artery. However, prior to performing percutaneous transluminal coronary angioplasty, and during the procedure itself, iodine containing dye or other contrast material is injected into a patient's coronary arteries through a catheter. This iodine solution is fluorescent and enables the coronary arteries to be clearly illustrated for the physician.
A serious problem associated with the use of such contrast solutions exists. The use of such solutions may lead to contrast-induced nephropathy. Contrast-induced nephropathy can result in transient or permanent renal impairment or failure of a patient's kidneys. It is well known that renal dysfunction is associated with the use of radiographic contrast media, and that the dysfunction may range from a transient slight increase in serum creatinine levels to renal failure requiring transient or long-term dialysis.
Many patients require revascularization of more than a single vessel. However, when there is danger of contrast-induced renal failure, the vessels are operated on in separate procedures at greatly increased cost and additional risk of arterial puncture. Therefore, it is highly desirable or imperative to eliminate the risk of renal failure.
Further, there are many other patients with chronic renal insufficiencies who must wait 24 to 48 hours in the hospital before undergoing percutaneous transluminal coronary angioplasty in order to space the kidney load associated with the contrast load. Still others, particularly the elderly with a pre-existing renal insufficiency, make up a large group in which angioplasty is avoided due to multi-vessel disease and multi-vessel intervention, which may lead to renal failure.
Contrast-induced nephropathy can be prevented if the contrast solution is kept away from the kidney. However, once the dye has been mixed with blood, the conventional method to separate the two is by filtration (for example, through dialysis). Dialysis relies on diffusion down a concentration gradient and is not completely effective if the concentration of dye in the blood to be filtered is low. Furthermore, the flow rates of conventional hemodialysis procedures are too high for patients who are undergoing angioplasty, and these patients typically do not tolerate wide fluctuations in blood pressure, as is common with hemodialysis.
Thus, a system and method for removing blood containing radiographic contrast media from the venous system of the heart before the blood circulates to the kidneys is desired for solving the aforementioned problems.